This commit adds two new command line switches dealing
with the potential need to automate/script the setting
of top's current sort field independent of the rcfile.

The -o (lower case) switch requires a lone valid field
name as an argument, from among the 42 currently used.
Then, it overrides the config file's Curwin->sortindx.

And since field names are now translatable, they could
diverge from those reflected in the documentation. So,
a 2nd switch of -O (upper case) is also provided which
outputs all names as translated and understood by top.

(now that we know a '.' + 2 spaces is squeezed to one)
(everything's perfectly justified, but it's just luck)